In the cognitive science and the medical field, the need for kinematics analysis and dynamics analysis based on a precise human-body model has been increasing. To conduct research on information processing in brain in the cognitive science, for example, information close to a human body, such as force applied to a joint and force generated by a muscle or a ligament, is necessary. In orthopedics, quantitative planning for an operation method which allow the motor function to be most recovered is an issue. To this end, precise analysis and simulation are required based on the shapes of muscles and bones.
The following references 1 to 3 include cases in which an attempt to model a human body precisely was made and motion analysis was performed with the use of the model. Especially in reference 2, kinematics analysis was performed to calculate a change in muscle length, and the change was applied to a physiological model of muscles to calculate muscular strength. In reference 3, muscular strength was calculated from the motion of a model.